Thanks to the other reviewers, I ordered up a size (or more). I ordered a large and they fit perfectly; I can't imagine being able to wear a smaller size because of the really tight band around the thigh. I ordered these Tri shorts because I wanted something with a minimal pad/chamois that didn't feel like a diaper. Previously, I bought a clearance pair of Orca Tri shorts that were wrong: not the color advertised (bright purple), returned for a bigger size, and a pad/chamois that feels like a diaper and uncomfortably digs into my back end. In normal everyday clothes, I wear about a size 6 (sometimes 8) pants, which often is a size small. But I'm discovering that Tri shorts are so tight that I would probably expect to be a size medium. I am 5' 5" and 136 lbs with a large waist and small hips. So, given that I am a size medium in triathlon clothes, I ordered up and got a large. Thanks so much to the previous reviewers for helping me make this sizing decision because otherwise I would've probably had another return and waste of shipping fees. I actually really like the lower waist line that dips below the belly button in these Pearl Izumi shorts. I will definitely wear these for my next sprint triathlon.UPDATE: I'm changing my mind on these shorts... I have a triathlon in 10 days, so I decided to try the shorts for a swim (oops, should have done that a while ago). They've been great for cycling so I haven't worried about it yet. But they were TERRIBLE for the swim. The tight band around the thigh (to keep them down and in place for cycling) didn't allow the shorts to fit tightly around the chamois area (i.e., they kept pulling the shorts down my thigh). So there was A LOT of movement, friction, and water leaking into the shorts. I think that ordering a bigger size to accommodate the tight leg band means that there is too much space/looseness in the rest of the shorts. So watch out for "ordering up a size" because it may introduce other dilemmas. Additionally, I discovered that I can't stand a fleece chamois (which these shorts have) because it adds to the friction and causes me a lot of discomfort in the chamois/crotch area. I had to hurriedly run downtown to our boutique Triathlon/cycling store to try on another brand (super expensive!) because I've only got a short time left to find a pair of shorts that will work for my triathlon. (By the way, my other Tri shorts (Orca) have a pad too big for running that digs into my rear end). Last minute anxiety and stress... wish I didn't have to go through this! Finding the RIGHT pair of shorts for each event is tougher than I thought.